The term “dust removal” in the technical field of textile machines and in the scope of the present invention should be understood to mean measures for the purpose of collecting and/or removing dusts that are formed during textile production or textile processing and are dispersed in the air, e.g. by fly lint, and for the prevention of harmful accumulations of dust forming at sensitive function points of the textile machine. In this case, the term “dust” not only covers dusts in the form of fibres and lint particles or fluff, but fundamentally all particles which are formed in textile technology and pass into the atmosphere.
Permanent sources of dusts of this type in the case of weaving and knitting machines are in particular unavoidable feed, braking and monitoring systems for threads of all types as well as devices for their guidance, deflection and control such as thread eyes or guide bars. Since most yarn qualities, but above all cotton threads, cause substantial fluff formation, the pieces of fluff are easily deposited on other machine elements, where they form tufts or clumps that gradually increase in size and as a result can impair the function of the respective textile machine. Therefore, it is generally known to equip textile machines of a wide variety of types with dust removal devices in order to remove, where possible, any dusts produced before they are deposited.
The dust removal devices known hitherto in textile machines largely operate with blower and/or suction devices (e.g. DE 79 26 685 U1, DE 32 19 467 A1, U.S. Pat. No. 3,422,640, EP 0 531 019 B1). Some of these have complex air distributor arrangements to enable blower and/or suction nozzles to be disposed at as many locations of the respective textile machine as possible. Dust removal devices integrated into thread feed devices are also known in this context (e.g. EP 1 053 196 B1, WO 01/18295), and also dust removal devices primarily for the purpose of keeping those regions of a circular knitting machine dust-free where textile threads are worked by knitting tools to form stitches (e.g. WO 95/09259, EP 0816 546 A2).
Therefore, dust removal devices of this type are technically complex and associated with a high energy consumption for the generation of compressed air and/or suction air. Blower and/or suction nozzles, moreover, frequently render access to the function points difficult, and this makes repairs and maintenance difficult.
In addition, devices are known for the purpose of removing dusts accumulating on moving webs of material, e.g. paper, textile or plastic webs, by electrostatically charging and/or discharging the material webs by using electrodes before the webs are fed into an suction station (e.g. WO 91/12095, DE 41 20 973 A1, DE 100 18 010 A1, DE 195 25 453 A1, DE 197 11 342 A1). This takes into consideration the physical phenomenon that both electrically non-conductive material webs and dust particles dispersed in the air are frequently electrostatically charged by contact and/or frictional electricity and particularly strong adhesion forces occur in the case of opposed polarities. The treatment of material webs with charge and/or discharge electrodes should therefore electrostatically neutralise dusts adhering to them and as a result reduce the electrostatic adhesion forces. However, such devices only allow the disposal of dusts, which are already deposited on a material web, e.g. a finished woven or knitted textile. Problems caused in textile machines in particular by dust and fly lint cannot be resolved with such devices.